A thick, warm cover you put on a bed, filled with very soft feathers. Those feathers are down — the fluffy layer under a bird's outer feathers, not the opposite of up.

A thick, warm cover you put on a bed一種鋪在床上、厚厚暖暖的被子 filled with very soft feathers裡面填的是非常柔軟的羽毛 Those feathers are down那些羽毛就是down the fluffy layer under a bird's outer feathers也就是鳥類外層羽毛底下那層蓬鬆的絨毛 not the opposite of up不是「up」的反義詞那個down

The first part is eider, a sea duck whose breast down is unusually light and warm, so a true eiderdown was once a rather special, expensive thing. Though actually, in everyday British English people often say eiderdown for any thick feather quilt, even when the filling is ordinary duck or goose down, or a mix.

The first part is eider前半部分eider指的是 a sea duck whose breast down is unusually light and warm一種胸前絨毛特別輕暖的海鴨 so a true eiderdown was once a rather special, expensive thing所以真正的eiderdown曾經是相當特別、昂貴的東西 Though actually, in everyday British English不過其實在英國的日常英文裡 people often say eiderdown for any thick feather quilt大家常常把任何厚的羽毛被都叫做eiderdown even when the filling is ordinary duck or goose down, or a mix就算裡面填的只是普通鴨絨、鵝絨、或混合絨毛也一樣

Older speakers in Britain use it a lot for the heavy cover that sits on top of the sheets; younger people more often say duvet. It sounds homely and a little old-fashioned, not like a shop label. You would not use it for a thin blanket or for a padded winter coat.

Older speakers in Britain use it a lot for the heavy cover that sits on top of the sheets英國的老一輩常常用這個字，指鋪在床單上那層厚重的被子 younger people more often say duvet年輕人比較常說duvet It sounds homely and a little old-fashioned聽起來有點家常、也有點老派 not like a shop label不像商店標籤那種說法 You would not use it for a thin blanket不會用來指薄毯子 or for a padded winter coat也不會用來指冬天的棉外套